Carbohydrates and Running

Carbohydrates (sugar, starch, and fiber) play an important role in maintaining a healthy diet and fueling your runs. Carbohydrates are stored in your muscles as glycogen, which your body taps into during a workout.

But not all carbohydrates are created equal. The more processed a carbohydrate is (like packaged foods and sweets) the more it becomes stripped of its nutrients, making its calories “empty.”

To fuel your body and your run, reach for complex carbohydrates like whole fruits and vegetables, dairy, whole grains, potatoes, and legumes. These foods provide a host of nutrients, including fiber, vitamin C, and calcium, that will help runners feel full and perform their best.

You can benefit from simple carbohydrates (like table sugar, maple syrup, or dextrose), which provide quick bursts of energy. This type of sugar (found in energy gels and chews) is good for on-the-run fuel because it is quickly absorbed and can help replenish the glycogen stores you’re depleting on a long run. You'll want to refuel regularly on the run before your muscles become fully depleted. Try to consume 30 to 60 grams every hour, depending on your intensity and also body size.

Carb-loading may be a runner’s favorite part about marathon day. But to do it properly, it’s important not to eat heaps of pasta for days on end—you’ll feel sluggish and it could lead to GI distress on race day. Instead, slowly increase your carbohydrate intake about three to seven days leading up to your race. For example, have oatmeal and fruit for breakfast, add a dinner roll to your salad, have a handful of pretzels as a snack, and add rice or other whole grains to your dinner.

Activity Level

Recommended Intake

Light activity (less than 1 hour per day)

1.3 to 2.3 g/lb. body weight

Moderate activity (1 hour per day)

2.3 to 3.2 g/lb. body weight

Extreme exercise program (4.5 to 6 hours per day)

4.5 to 5.5+ g/lb. body weight

Source: Position of the Academy of Nutrition and Dietetics, Dietitians of Canada
The American College of Sports Medicine: Nutrition and Athletic Performance